Esterase and protease activities of Bacillus spp. from afitin, iru and sonru; three African locust bean (Parkia biglobosa) condiments from Benin

Fifty strains of Bacillus spp. comprising Bacillus subtilis and Bacillus licheniformis previously isolated from afitin, iru and sonru were examined for esterase and protease activities. The electrophoretic profiles of fermented African locust bean protein (ALBP), using strains presenting the highest protease activities in casein agar, were analyzed by SDS-PAGE to select strains with good ability to be used as starter cultures. All the Bacillus spp. tested showed esterase activity against tributyrin with high variability among strains. Strains showing the highest esterase activities were B. subtilis, primarily isolated from iru, sonru and lastly in afitin. Only 62% (31/50) of the Bacillus strains tested showed perceptible, but highly variable protease activity in casein agar. Bacillus strains showing the highest protease activities comprised strains of B. subtilis isolated from afitin and iru and strains of B. licheniformis isolated from iru and sonru. A B. subtilis strain isolated from afitin showed high esterase as well as high protease activity. The electrophoretic profile by SDS-PAGE of ALBP fermented by the Bacillus spp. having the highest protease activities showed degradation products with a wide range of molecular size between 4 and 250 kDa. Variability of the characteristics of the Bacillus spp. tested give new opportunities for their use as starter culture for products development.Keywords: Bacillus subtilis, bacillus licheniformis, fermentation, esterase and protease activity, SDS-PAG

Sensory and physicochemical profiling of traditional and enriched gari in Benin

Gari is a roasted fermented granular product made from cassava in many African countries. It is consumed raw, or added with water, or cooked into a paste. Up to now, gari enriched with palm oil and/or soybean is not available on Beninese markets. To our knowledge, no sensory profiling using appropriate methodology has been conducted on gari in Benin. The sensory studies on gari in Benin and other African countries only included general descriptors (appearance, taste, odor). The aim of our study was to establish a detailed sensory and physicochemical profile of nine traditional and three enriched gari made using different processes in Benin. Fifteen sensory descriptors of raw gari, and gari added with water, were generated and scored using quantitative descriptive analysis. The enriched gari differed from traditional gari mainly in color and odor, while their swelling capacity, texture during chewing, and light sour taste were similar. Marked variability in particle size, particle heterogeneity, water absorption, and sour taste was found among traditional gari. The physicochemical characteristics, such as degree of starch gelatinization, L‐lactic acid, and β‐carotene contents, were highly variable among the 12 gari. Multifactor analysis revealed highly significant correlations between some physicochemical and sensory properties. The addition of soybean and/or palm oil did not affect most of the sensory properties of the traditional gari. The acceptability of these enriched gari with higher nutritive value by Beninese consumers should be tested to develop marketing strategies

Comparing the quality of two traditional fried street foods from the raw material to the end product: The Beninese cowpea‐based ata and the Italian wheat‐based popizza

Abstract Street food plays a recognized socioeconomic role, offering opportunities of employment particularly for women and providing cheap food to lower income people. West Africa is characterized by a great diversity of traditional foods, widely consumed but poorly investigated. Ata is a fried dough made of cowpea flour, very popular in Benin. In Southern Italy, popizza is prepared in a very similar way as ata, but using wheat flour. This work aimed at comparing the main physicochemical characteristics of ata and popizza, from the raw material to the end product. Cowpea flour showed significantly higher levels of proteins (23.25 vs. 13.48 g 100 g−1 on dry matter), total phenolic compounds (0.73 vs. 0.41 mg g−1 of ferulic acid d.m.), antioxidant activity (2.84 vs. 0.86 μmoL Trolox g−1 d.m.), as well as higher water absorption capacity (1.01 vs. 0.61 g water per gram flour) and particularly higher water solubility index (23.01 vs. 6.69 g 100 g−1) than wheat flour. The two flours showed different pasting characteristics: starch swelling occurred at a lower temperature in cowpea than in wheat flour and produced a less viscous gel. Due to absence of gluten and limited viscosity of starchy fraction, ata was less porous and more springy than popizza. Moreover, ata showed higher oil uptake than popizza (22.2 vs. 14.1 g oil 100 g−1 product) and was also characterized by a browner surface than popizza. Knowledge about the quality features of these traditional foods and their raw material could enhance their marketing, with positive effects on local economy

Effects of Garlic Extract and Lemon Juice on the Shelf Life of Fermented and Dried Fish Fillets (Lanhouin) during Storage

The effect of natural additives (lemon juice, garlic extract or their mixture) on the shelf life of Lanhouin fillets, a fermented fish, was investigated by  monitoring the microbiological, physicochemical and sensory changes in treated fillet samples and control. All analyzed samples showed a decreasing  trend in water activity and total viable count during the storage period, while an increasing trend was recorded for the pH, total volatile nitrogen and  biogenic amines at both 4 and 30°C storage conditions. The highest histamine content in the treated filet samples was 10.5 mg/kg while the maximal  threshold suggested by European regulation for such fishery products is 20 mg/100g. The sensory evaluation revealed that the Lanhouin fillets treated  with lemon juice, garlic extract or their mixture and stored at 4°C for 90 days exhibited a significantly higher visual appearance, odour and overall  acceptability scores compared to those stored at 30°C. These ingredients which are readily available and affordable could be valorized in the production  of Lanhouin as preservative agents in the cottage industry of West African countrie